A device (e.g., an ultrasound or, more particularly, a transcranial Doppler (TCD) device) may include a probe (e.g., a movable, robotic probe) configured to image or measure physiological data of a subject or patient. The medical device may also include at least one camera for aiding in proper automatic alignment of the probe with respect to an anatomical feature of a human, or to properly register the medical device with respect to the anatomical feature of the human, for improving accuracy and precision of the sampled data. A housing of the medical device may also define a cavity through which the probe protrudes. The probe moves within a boundary defined by the cavity. During the operation of the probe, particles (e.g., hair) and liquid (e.g., blood and gel) may fall into the cavity, which may be hazardous to the electronic and mechanical components of the device that are exposed by the cavity.